Add rospeex to hydro/distribution.yaml

## Abstract
Rospeex is a cloud-based multilingual speech communication package. The package allows the users to add speech recognition/synthesis functionality to their robots. Rospeex supports speech recognition and speech synthesis in Japanese, English, Chinese, and Korean. By using its APIs in Python or C++, you can write a sample function for a simple spoken dialogue within 10 lines. 

## Sample codes
Sample codes are available at http://rospeex.org/top/